1. Field of the Invention
This invention generally relates to the field of wireless communications. More particularly, the present invention relates to a novel method and apparatus for a mobile station application to receive and transmit raw packetized data in a wireless communication system.
2. Description of Related Art
A. Wireless Communications
Recent innovations in wireless communication and computer-related technologies, as well as the unprecedented growth of Internet subscribers, have paved the way for mobile computing. In fact, the popularity of mobile computing has placed greater demands on the current Internet infrastructure to provide mobile users with more support. The life blood of this infrastructure is the packet-oriented Internet Protocol (IP) which provides various services, including the addressing and routing of packets (datagrams) between local and wide area networks (LANs and WANs). IP protocol is defined in Request For Comment 791 (RFC 791) entitled, “INTERNET PROTOCOL DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION,” dated September 1981.
The IP protocol is a network layer protocol that encapsulates data into IP packets for transmission. Addressing and routing information is affixed to the header of the packet. IP headers, for example, contain 32-bit addresses that identify the sending and receiving hosts. These addresses are used by intermediate routers to select a path through the network for the packet towards its ultimate destination at the intended address. Thus, the IP protocol allows packets originating at any Internet node in the world to be routed to any other Internet node in the world. On the other hand, a transport layer, which comprises either a Transmission Control Protocol (TCP) or a User Datagram Protocol (UDP), is used to address to particular applications.
The current trend is for mobile users to use mobile computers, such as laptop or palmtop computers, in conjunction with wireless communication devices, such as cellular or portable phones, to access the Internet. That is, just as users conventionally employ “wired” communication devices to connect their computers to land-based networks, mobile users will use wireless communication devices, commonly referred to as “mobile stations” (MSs), to connect their mobile terminals to such networks. As used herein, the mobile station or MS will refer to any subscriber station in the public wireless radio network.
FIG. 1 (Prior Art) illustrates a high-level block diagram of a wireless data communication system in which the MS 110 communicates with an Interworking Function (IWF) 108 via a Base Station/Mobile Switching Center (BS/MSC) 106. The IWF 108 serves as the access point to the Internet. IWF 108 is coupled to, and often co-located with, BS/MSC 106, which may be a conventional wireless base station as is known in the art. Another standard protocol that addresses the wireless data communication system is the 3rd Generation Partnership Project 2 (“3GPP2”) entitled “WIRELESS IP NETWORK STANDARD,” published in December 1999. The 3G Wireless IP Network Standard, for example, includes a Packet Data Serving Node (“PDSN”), which functions like the IWF 108.
There are various protocols that address the data communications between the MS 110 and the IWF 108. For example, Telecommunications Industry Association (TIA)/Electronics Industries Association (EIA) Interim Standard IS-95, entitled “MOBILE STATION-BASE STATION COMPATIBILITY STANDARD FOR DUAL-MODE WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEM,” published in July 1993, generally provides a standard for wideband spread spectrum wireless communication systems. Moreover, standard TIA/EIA IS-707.5, entitled “DATA SERVICE OPTIONS SERVICES,” published in February 1998, defines requirements for support of packet data transmission capability on TIA/EIA IS-95 systems and specifies packet data bearer services that may be used for communication between the MS 110 and the IWF 108 via the BS/MSC 106. Also, the TIA/EIA IS-707-A.5 standard, entitled “DATA SERVICE OPTIONS FOR SPREAD SPECTRUM SYSTEMS: PACKET DATA SERVICES,” and the TIA/EIA IS-707-A.9 standard, entitled “DATA SERVICE OPTIONS FOR SPREAD SPECTRUM SYSTEMS: HIGH-SPEED PACKET DATA SERVICES,” both published in March 1999, also define requirements for packet data transmission support on TIA/EIA IS-95 systems. In addition, another standard protocol that addresses communications between the MS 110 and the IWF 108 is the TIA/EIA IS-2000, entitled “INTRODUCTION TO CDMA 2000 STANDARDS FOR SPREAD SPECTRUM SYSTEMS,” published in July 1999.
IS-707.5 introduces communication protocol option models between the MS 110 and the BS/MSC 106 (the Um interface), and between the BS/MSC 106 and the IWF 108 (the L interface). For instance, a Relay Model represents the situation where a Point to Point Protocol (PPP) link exists on the Um interface between the MS 110 and the IWF 108. The PPP protocol is described in detail in Request for Comments 1661 (RFC 1661), entitled “THE POINT-TO-POINT PROTOCOL (PPP).”
FIG. 2 (Prior Art) is a diagram of the protocol stacks in each entity of the IS-707.5 Relay Model. At the far left of the figure is a communication protocol stack, shown in conventional vertical format, showing the protocol layers running on the MS 110. The MS 110 protocol stack is illustrated as being logically connected to the BS/MSC 106 protocol stack over the Um interface. The BS/MSC 106 protocol stack is, in turn, illustrated as being logically connected to the IWF 108 protocol stack over the L interface.
The operation depicted in FIG. 2 is as follows: an upper layer protocol 200 entity, such as an application program running on the MS 110, has a need to send data over the Internet. A representative application may be a web browser program (e.g., Netscape Navigator™, Microsoft Internet Explorer™). The web browser requests a Universal Resource Locator (URL), such as HYPERLINK “http://www.Qualcomm.com/”. A Domain Name System (DNS) protocol, also in the upper layer protocol 200, translates the textual host name www.Qualcomm.com to a 32-bit numeric IP address by the use of a domain name resolution, which translates names to addresses in the Internet. The Hypertext Transfer Protocol (HTTP), which is also an upper layer protocol 200, constructs a GET message for the requested URL, and specifies that TCP will be used to send the message and for HTTP operations. The transport layer 202 uses port 80, which is known in the art, as the destination port to route the HTTP operations to the application.
The TCP protocol, which is a transport layer protocol 202, opens a connection to the IP address specified by DNS and transmits the application-level HTTP GET message. The TCP protocol specifies that the IP protocol will be used for message transport. The IP protocol, which is a network layer protocol 204, transmits the TCP packets to the IP address specified. The PPP, which is a link layer protocol 206, encodes the IP packets and transmits them to the relay layer protocol 208. An example of the relay layer protocol 208 may be the illustrated TIA/EIA-232F standard, which is defined in “INTERFACE BETWEEN DATA TERMINAL EQUIPMENT AND DATA CIRCUIT-TERMINATING EQUIPMENT EMPLOYING SERIAL BINARY DATA INTERCHANGE,” published in October 1997. It is to be understood that other standards or protocols known to artisans of ordinary skill in the art may be used to define the transmission across the layers. For example, other applicable standards may include the “UNIVERSAL SERIAL BUS (USB) SPECIFICATION, Revision 1.1,” published in September 1998, and the “BLUETOOTH SPECIFICATION VERSION 1.0A CORE,” published in July 1999. Last, the relay layer protocol 208 passes the PPP packets to a Radio Link Protocol (RLP) 210 and then to the IS-95 protocol 212 for transmission to the BS/MSC 106 over the Um interface. The RLP protocol 210 is defined in the IS-707.2 standard, entitled “DATA SERVICE OPTIONS FOR WIDEBAND SPREAD SPECTRUM SYSTEMS: RADIO LINK PROTOCOL,” published in February 1998, and the IS-95 protocol is defined in the IS-95 standard identified above.
A complementary relay layer protocol 220 on the BS/MSC 106 receives the PPP packets over the Um interface through a IS-95 layer 218 and then a RLP layer 216. The relay layer protocol 220 passes them over the L interface to a relay layer protocol 228 on the IWF 108. A PPP protocol link layer 226 on the IWF 108 receives the PPP packets from the relay layer protocol 228, and terminates the PPP connection between the MS 110 and the IWF 108. The packets are passed from the PPP layer 226 to a IP layer 224 on the IWF 108 for examination of the IP packet header for final routing, which in this scenario is www.Qualcomm.com.
Assuming that the ultimate destination of the IP packets generated by the MS 110 is not the IWF 108, the packets are forwarded through the network layer protocols 224, and link layer protocols 225 to the next router (not shown) on the Internet. In this manner, IP packets from the MS 110 are communicated through the BS/MSC 106, and the IWF 108 towards their ultimate intended destination in the Internet in accordance with the IS-707.5 standard relay model.
Before the MS 110 packets reach their destination, the data link connection must be established first. As specified in RFC 1661, this requires each end of the point-to-point link (i.e., the PPP protocols 206 and 226) to first send PPP Link Control Protocol (LCP) packets in order to establish, configure and test the data link connection. After the link has been established by the LCP, the PPP protocol 206 may then send Network Control Protocol (NCP) packets to configure the network layer protocols 204 and 224. The NCP for IP in PPP links is the IP Control Protocol (IPCP). IPCP is described in detail in Request for Comment 1332 (RFC 1332), entitled “THE PPP INTERNET PROTOCOL CONTROL PROTOCOL (IPCP),” published in May 1992. Before IPCP negotiation, however, an authentication phase may be needed. After each of the network layer protocols has been configured, packets from each network layer protocol can be sent over the link between them.
B. Application Program Interface
Most, if not all, of the processes supporting the communication protocol stack on the MS 110 are executed by application programs. Generally, conventional data networks employ application program interfaces (APIs) to enable application programs running on one computer to communicate with application programs running on another computer. The APIs utilize “sockets,” which shelter the invoking applications from differences in the protocols of the underlying network. To achieve inter-networked communications, APIs comprise functions, which allow the applications, for example, to open a socket, transmit data to the network, receive data from the network, and close the socket. Common network programming interfaces include Berkeley Systems Development (BSD) sockets interface, which operates under a Unix™ operating system, and Windows™ Sockets Interface (WinSock™), which operates under a Windows™ operating system.
Because neither BSD sockets nor WinSock™ supports the communication protocol stack on the wireless MS 110 (see FIG. 2), a novel API supporting such a stack is needed. In particular, what is needed is a novel method and apparatus for a mobile station application to receive and transmit raw packetized data in a wireless communication system.